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The population dynamics of developing somatic embryos of carrot (Daucur carota L.) was investigated in batch and fed-batch cultures using modified Murashige and Skoog medium. These substrate limitations coincided not only with stoppage of biomass increase, but also with the increase in total concentration of embryos as... |
Immobilization of phospholipase D from cabbage was studied with the aim of stabilizing the enzyme for its use in synthesis of phospholipids. It was shown that phospholipase D can be immobilized by adsorption to polymeric carriers containing long chain anchor groups such as octadecyl, octyl, or other alkyl residues. Sta... |
The biochemical conversion of cellulosic biomass to ethanol, a promising alternative fuel, can be carried out efficiently and economically using the simultaneous saccharification and fermentation (SSF) process. The SSF integrates the enzymatic hydrolysis of cellulose to glucose, catalyzed by the synergistic action of c... |
Thermotoga maritima, among the most thermophilic eubacteria currently known, produces glucose isomerase when grow in the presence of xylose. The purified enzyme is a homotetramer with submit molecular Wight of about 45,000. It has a number of features in common with previously described glucose isomerases-pH optimum of... |
The activity of bilirubin oxidase toward bilirubin was studied in a liquid/solid two-phase low-water organic system using a simple spectrophotometric assay to follow the reaction. The enzyme was lyophilized from aqueous solution before being suspended in the organic solvent reaction medium. The activity was significant... |
The storage stability of bilirubin oxidase was studied in water-in-oil CTAB microemulsions with a chloroformrich continuous organic phase. The kinetics of the inactivation process were best described by a double exponential equation. Approximately half of enzymatic activity was lost during a "fast" phase with a half li... |
Fragment B of protein A conjugated with fluorescein at various lysine residues is prepared and separated by using a DEAE column in anion-exchange chromatography. The binding of IgG Fc to fragment B contributes to an additional positive electric potential around fragment B. The change in the local electrostatic environm... |
Saccharomyces cerevisiae cells immobilized in a calcium alginate fiber reactor were used as a source of alcohol dehydrogenase for the NAD(+)-to-NADH reaction. The reaction was catalyzed by enzyme in cells on the surface of the fiber. Internal diffusional effects were present. The enzyme cell concentration was optimized... |
Microbial metabolism provides at mechanism for the conversion of substrates into useful biochemicals. Utilization of microbes in industrial processes requires a modification of their natural metabolism in order to increase the efficiency of the desired conversion. Redirection of metabolic fluxes forms the basis of the ... |
A two-stage culture strategy was studied for continuous high-level production of a foreign protein in the chemically inducible T7 expression system. The first stage is dedicated to the maintenance of plasmid-bearing cells and the second stage to the target protein synthesis by induction of cells coming from the first s... |
The gp41 polypeptide of human immunodeficiency virus (HIV) contains an immunosuppressive domain, an epitope which elicits specific cytolytic T cell responses to HIV, and a complement Clq interactive domain. In addition, a synthetic peptide called CS3, derived from gp41 (amino acids 576-593 of gp160) and contiguous with... |
Tyrosyl ring motions in alpha-lytic protease were investigated by solid-state deuterium nuclear magnetic resonance (NMR) spectroscopy in lyophilized enzyme powder, in powder suspended in organic solvents, and in aqueous crystals. Ring flipping rates were determined by examining deuterium quadrupole echo line shapes. Of... |
The activity of lipases from Rhizopus delemar, Rhizopus arrhizus, and Penicillium simplicissimum entrapped in microemulsions formulated by bis-(2-ethylhexyl)sulfo-succinate sodium salt (AOT) in isooctane has been studied in esterification reactions of various aliphatic alcohols with fatty acids. The effect of the natur... |
The protease trypsin was immobilized to porous glass in both the presence and absence of acetylated soybean trypsin inhibitor (STI) to determine whether immobilization could alter enzyme activity in favor of aminolysis over hydrolysis. Actiive-site titration with 4-methylumbelliferylguanidinobenzoate (MUGB) showed that... |
The concept of micelle-supported electroenzymology is demonstrated using a system consisting of the membrane enzyme Escherichia coli fumarate reductase (FRD), the amphiphilic coenzyme analogue decylubiquinone (DU), the micelle-forming surfactant n-octyl glucoside (OG), and a gold electrode. The OG micelles provide a hy... |
It is demonstrated that a two-enzyme component synergistic model can account for the observation that the degree of synergism goes through a maximum as the total enzyme concentration is increased. The degree of synergism is low at low enzyme concentration because the extent of conversion is low and therefore the cellul... |
Growth of Bacillus subtilis TN106[pAT5] and synthesis of plasmid-encoded protein (alpha-amylase) are investigated in batch, continuous, and fed-batch cultures using a defined medium containing glucose and/or starch as the carbohydrate source. The batch culture studies reveal that reduced availability of arginine hamper... |
In nitrogen-limited media, growth and fatty acid formation by the oleaginous yeast Rhodotorula glutinis, i.e., yield and fatty acid cell content, have been characterized regarding carbon and nitrogen availabilities. It was shown that the formation of fatty acid free biomass was limited by nitrogen availability, whereas... |
Affinity cosurfactants, consisting of hydrophilic ligands derivatized with hydrophobic tails, increase the efficiency of selective protein recoveries using reversed micelles by extending the operating range of pH and salt concentration over which an extraction can be performed. Three different affinity cosurfactant-pro... |
The selectivity of protein extraction by reversed micellar solutions can be improved by the addition of affinity cosurfactants bearing ligands which bind strongly to the target protein. The interactions between cosurfactant and protein, as well as the interfacial activity of both the free cosurfactant and the protein-c... |
Measuring the reversible thermal unfolding of enzymes is valuable for quantifying the effects of environmental factors on the thermodynamic stability of proteins. The thermal unfolding behavior of enzymes is typically studied using calorimetry or optical techniques such as circular dichroism, fluorescence, or light sca... |
The purpose of this study was to design a biomedical reactor that reduces plasma cholesterol when incorporated in an in vivo extracorporeal system. Phospholipase A(2), immobilized onto Agarose beads and housed inside the bioreactor, modifies plasma low density lipoprotein (LDL) into a form that is rapidly removed from ... |
To investigate the expression and function of surfactant protein A (SP-A) in lung in rats with acute lung injury (ALI) induced by severe acute pancreatitis (SAP). |
Cefetamet pivoxil is an oral, third-generation cephalosporin whose broad spectrum of antibacterial activity and favorable pharmacokinetic profile make it particularly suitable for the treatment of a wide range of infectious diseases. Cefetamet has high in vitro activity against both gram-positive and gram-negative bact... |
Fluoroquinolones have broad antibacterial spectra and are active against most Gram-negative and many Gram-positive species. They exhibit excellent oral bioavailability, extensive tissue penetration, low protein binding, and a long elimination half-life. This review compares and contrasts the pharmakonetics of some quin... |
A strain of Acinetobacter baumannii 6B92 isolated from the blood culture of a patient at the Edinburgh Royal Infirmary i 1985 was found to be resistant to imipenem, all classes of cephalosporins and penicillins. Extraction of the soluble proteins of the cell and isoelectric focusing revealed the presence of two beta-la... |
S fimbrial adhesins (Sfa) represent virulence factors of E. coli wild-type strains causing urinary tract infections and meningitis of the new born. In order to determine the influence of subinhibitory concentration of antibiotics on the expression of the sfa gene cluster, a wild-type strain carrying the lacZ gene, codi... |
Cefuroxime is the first commercially-available second-generation cephalosporine to be widely used in therapy; it is a semi-synthetic cephalosporin obtained from the 7-cephalosporanic acid nucleus of cephalosporin C. Cefuroxime axetil is the acetoxyethyl ester of cefuroxime. The majority of micro-organisms associated wi... |
In-vitro susceptibility of 7301 clinical isolates of Gram-negative bacilli, originating from hospitals at and around Bratislava, to amikacin was evaluated during the years 1990-1992. In 1990 amikacin resistance represented 4.1%, in 1991 it increased to 7.3% and in 1992 a slight decline to 6.4% was observed. In Slovakia... |
Fleroxacin is a new oral and intravenous trifluoroquinolone with a half-life of 10-12 h. This new quinolone has excellent bioavailability, good tissue penetration, low protein binding and a low rate of metabolism. Serum concentrations following oral and intravenous administration are identical, allowing the clinician t... |
Serovars of Salmonella resistant to ampicillin, third-generation cephalosporins and aminoglycosides but sensitive to chloramphenicol, cefoxitin and ceftibuten emerged in one pediatric hospital of Buenos Aires. All isolates expressed AAC(6')-I and AAC(3)-V enzyme activities, making them resistant to all aminoglycosides ... |
rBPI(23) is a recombinant protein based upon the N-terminal sequence of bactericidal permeability increasing protein (BPI), a protein present in the granules of polymorphonuclear leukocytes. BPI has antibacterial activity against Gram-negative organisms and potent endotoxin neutralising properties. rBPI(23) has been de... |
Methicillin resistance in staphylococci is primarily due to the methicillin resistance determinant which produces an additional low affinity penicillin-binding protein PBP2'. Expression of PBP2' is controlled by its own regulatory element, and shares also the same induction system as beta-lactamases. However, methicill... |
Many antimicrobial agents including new quinolones (NQs) influence the cellular defense mechanisms such as polymorphonuclear leukocytes (PMNs), macrophages and lymphocytes. We examined the effects of NQs on superoxide (SO) production of PMNs following stimulation of phorbol myristate acetate (PMA). Ofloxacin (OFLX) and... |
Trypanothione reductase (TR) is the primary enzyme responsible for the reduction of trypanothione, the analog of glutathione found in trypanosomatidae. We have discovered a series of diphenylsulfides which are potent inhibitors of TR and have no activity on mammalian glutathione reductase. These compounds are also acti... |
RMP-7, a nine-amino acid bradykinin analogue, has been shown in animals to temporarily increase the permeability of the blood brain barrier to small molecules including amphotericin B, when administered intravenously. We sought to evaluate the safety of escalating doses of RMP-7 administered to human volunteers with th... |
The two beta-lactamase inhibitors, sulbactam and clavulanic acid, exhibit high affinity (K(I) < 10(-6)mol/l) for the beta-lactamases of Gram-negative organisms with predominantly penicillinase activity and much less affinity (especially clavulanic acid) for organisms with predominantly cephalosporinase activity. In tes... |
The most common problems limiting the medical use of aminoglycosides have been the nephro- and oto-toxicities and the increasing bacterial resistance. It has been shown that encapsulation of drugs into liposomes enhances their efficacy while reducing their toxicities. The present in vitro study was designed to evaluate... |
A total of 182 Salmonella enterica serotype Typhi isolated from three hospitals in Hong Kong from 1986 to 1992 were tested for their susceptibility to 21 antimicrobial agents. Four percent or less were resistant to chloramphenicol, ampicillin, some of the cephalosporins, nalidixic acid, tetracycline and trimethoprim an... |
During a study of piperacillin resistance among aerobic Gram-negative bacteria, 18 resistant strains of Enterobacter cloacae were obtained from a General Hospital in Rotterdam and 13 from a University Hospital in Amsterdam. The patterns of antibiotic susceptibilities were different: the Amsterdam strains were generally... |
Massive localized lymphedema is a benign soft tissue lesion that usually presents as a large mass in morbidly obese adults. The diagnosis may be challenging as it can mimic other lesions, including well-differentiated liposarcoma. We report 2 cases of massive localized lymphedema with unusual presentation. The first ca... |
The growing availability of sequence information from diverse parasites through genomic and transcriptomic projects offer new opportunities for the identification of key mediators in the parasite-host interaction. Functional genomics approaches and methods for the manipulation of genes are essential tools for decipheri... |
Microbial production of 2,3-butanediol by Klebsiella oxytoca occurs under conditions of an oxygen limitation. The extent to which substrate is oxidized to 2,3-butanediol and its coproducts, (acetic acid, acetoin, and ethanol) and the relative flow rates of substrate to energetic and biosynthetic pathways are controlled... |
A series of Bombyx mori nuclear polyhedrosis virus (Bm-NPV) transfer vectors has been developed containing various lengths of the polyhedrin promoter, including sequences 3' of the initiation codon. The ATG initiation codon was mutated in some of these vectors to allow for the production of authentic nonfusion proteins... |
This research assessed the effect of oxygen exposure on the methanogenic activity of anaerobic granular sludges. The toxicity of oxygen to acetoclastic methanogens in five different anaerobic granular sludges was determined in serum flasks with effective gas-to-liquid volumes of 4.65 to 1. The amount of oxygen that cau... |
In this work the effects of environmental parameters on the performance of solid substrate fermentation (SSF) for protein production are studied. These parameters are (i) air flow rate, (ii) inlet air relative humidity, (iii) inlet air temperature, and (iv) the heat transfer coefficient between the outer wall of the fe... |
The adhesion forces between various surfaces were measured using the "surface forces apparatus" technique. This technique allows for the thickness of surface layers and the adhesion force between them to be directly measured in controlled vapor or liquid environments. Three types of biological surfaces were prepared by... |
The strong interaction of hexa-histidine fusion proteins with metal chelate adsorbents was utilized to immobilize beta-galactosidase with a hexa-histidine peptide at the N-terminus to the Ni(2+)-nitrilotriacetic acid adsorbent. The fusion protein was cloned and expressed in Escherichia coli. The purified soluble fusion... |
The steady-state metabolic parameters for a hybridoma cell line have been determined in continuous suspension-perfusion culture over a wide range of perfusion rates and cell bleed rates. Significant increases in viable cell concentrations and volumetric productivities were achieved at high perfusion rates and low cell ... |
Lipase from Candida cylindracea (CCL) was incorporated into polymerizable positively charged dialkylammonium bromide surfactant vesicles. The enzyme was incorporated by the use of the dehydration-rehydration method or by incubation. In the latter case, trapping efficiencies of up to 100% could be obtained. Activities o... |
SPA::EcoRI fusion protein was produced by Escherichia coli JM103 carrying the multicopy expression plasmid pMTC48, the multicopy repressor plasmid pRK248, and the multicopy protection plasmid pEcoR4 in a 60-L working volume airlift tower loop reactor on M9 minimal medium with glucose. Cell mass concentration, total cel... |
The effect of the growth phase of Spodoptera frugiperda (Sf9) cells on the production of recombinant proteins (beta-galactosidase and glucocerebrosidase) was investigated. Cells infected with the recombinant Autographa californica nuclear polyhedrosis virus at the late exponential and stationary phases yielded low quan... |
Insect cell culture and the baculovirus vector expression system have emerged to be a promising production technique for heterologous proteins. In this article, expression characteristics for membrane-bound epoxide hydrolase are examined. A generic process is presented whereby cells are grown in serum-free media supple... |
The factors contributing to protein aggregation in albumin ultrafiltration were investigated as a function of operation conditions. The nature of protein deposits was examined by electron microscopy. Protein aggregation appears to occur as a result of rapid supersaturation of protein molecules and high solvent velocity... |
A reaction engineering model for the degradation of an inhibitory substrate by a steady-state biofilm is presented. The model describes both the metabolic rate controlling behavior of this substrate in the biofilm and the effect of diffusion limitation caused by an arbitrary substrate on the active biofilm thickness. A... |
A novel procedure is proposed for determining distributions of rate properties and correlations of rate with state properties of microbial cell populations. The procedure is novel in that it uses transient data, and thus, it does not require that the population be in balanced growth, although it requires that the popul... |
Gluco-oligosaccharides were synthesized through the enzymatic condensation of D-glucose at high concentration using a commercial almond beta-glucosidase. The synthesis reactions were carried out with both free and immobilized enzyme, with or without sorbitol, an efficient depressor of water activity (a(w)) in the prese... |
Fusarium solani pisi recombinant cutinase, solubilized in AOT/isooctane-reversed micelles, was used to catalyze the esterification of fatty acids with aliphatic alcohols. Some relevant parameters for the enzyme activity such as pH, W(o) (water/surfactant molar ratio), temperature, and substrate concentration were optim... |
Alcohol dehydrogenase (E. C. 1.1.1.1) from Thermoanaerobium brockii at 25 degrees C and at 65 degrees C is more active with secondary than primary alcohols. The enzyme utilizes NADP and NADPH as cosubstrates better than NAD and NADH. The maximum velocities (V(m)) for secondary alcohols at 65 degrees C are 10 to 100 tim... |
Using permeabilized Zymomonas mobilis or glucose-fructose oxidoreductase isolated from this microorganism a model system for biosensors with a protein confined NADP(H) cofactor for the determination of glucose, fructose, gluconolactone, and sorbitol was developed. Either permeabilized microorganisms containing the oxid... |
Genetically engineered Saccharomyces cerevisiae strains that express Escherichia coli beta-galactosidase gene are able to bioconvert lactose or whey into fructose-1,6-diphosphate (FDP). High FDP yields from whey were obtained with an appropriate ratio between cell concentration and inorganic phosphate. The biomass of t... |
Several examples of two-step sequential reactions exist where, because of the poor equilibrium conversion by the first reaction, it is desirable to conduct the two reactions simultaneously. In such a scheme, the product of the first reaction is continuously removed by the second reaction, thus not allowing the first re... |
We have developed a strategy for immobilization-stabilization of penicillin G acylase (PGA) from Kluyvera citrophila by controlled multipoint covalent attachment to agarose-aldehyde gels. This enzyme is composed by two dissimilar subunits noncovalently bound. Thus, in this article we establish clear correlations betwee... |
We studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm ... |
Two fractions of substrate in microcrystalline cellulose which differ in their adsorption capacities for the cellulases and their susceptibility to enzymatic attack have been identified. On the basis of a two-substrate hypothesis, mathematical models to describe enzyme adsorption and the kinetics of hydrolysis have bee... |
A semicontinuous process has been developed to recover heterologous proteins at increased concentrations and purities. Proteins attached to mammalian cell membranes by glycosylphosphatidylinositol (GPI) anchors can be selectively released into the supernatant by the enzyme phosphatidylinositol-phospholipase C (PI-PLC).... |
Enzymes are potential catalysts for a wide range of large-scale chemical synthesis steps, particularly when the creation of a specific chiral center is desired. The efficient recycling of the enzyme catalyst and the removal of carryover impurities were crucial factors in the improvement of a stereoselective ester hydro... |
A simple mathematical model is developed to help explain the complex population dynamics of an Escherichia coli host-plasmid expression/excretion system for beta-lactamase within single- and two-stage reactors. The model successfully integrates the individual regulatory (tac promoter induction), genetic (runaway plasmi... |
The microbial degradation of quinoline by Comamonas acidovorans was studied in a laboratory scale stirred tank reactor. In continuous culture experiments using quinoline as a sole source of carbon and nitrogen, it was shown by means of mass balances that quinoline was converted completely to biomass, carbon dioxide, an... |
Protein extractions using aerosol OT (AOT)-isooctane reverse micelle solutions have been studied to explore the potential for separating and enriching proteins with the reversed micellar extraction. The effects of pH, ionic strength, and different cations of chlorides in a bulk aqueous phase and of AOT concentration in... |
The effect of surfactants on the heterogeneous enzymatic hydrolysis of Sigmacell 100 cellulose and of steam-exploded wood was studied. Certain biosurfactants (sophorolipid, rhamnolipid, bacitracin) and Tween 80 increased the rate of hydrolysis of Sigmacell 100, as measured by the amount of reducing sugar produced, by a... |
Much of the current cell technology has enabled increased antibody production levels due to judicious nutrient feeding to raise cell densities and design better bioreactors. This study demonstrates that hybridomas can be hyperstimulated to produce higher immunoglobulin (lg) levels by suppressing cell growth and increas... |
The enantioselective esterification of racemic ibuprofen, catalyzed by a Candida cylindracea lipase, was studied in a water-in-oil microemulsion (AOT/isooctane). By using n-propanol as the alcohol, an optimal W(0) ([H(2)O]/[AOT] ratio) of 12 was found for the synthesis of n-propyl-ibuprofenate at room temperature. The ... |
The anchorage-dependent cell line, MRC-5, was cultivated successfully on glass fibers with diameters ranging from 24 to 120 mum, despite vast differences in substrate curvature. Multilayer cell growth was observed, particularly for fiber diameters 30 mum and below, which differed from the typical monolayer growth obser... |
Commercially available lactase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) enzymes produced from Kluyveromyces fragilis and Kluyveromyces lactis were accessed as catalysts for use in the production of beta-galactopyranosides of various alcohols using lactose as galactosyl donor. The yield of galactoside was enha... |
Several researchers have demonstrated that the presence of a heterologous protein in recombinant Escherichia coli elicits a response similar to the heat-shock response, which includes enhanced protease expression. The present work detects, quantifies, and characterizes intracellular protease activity in E. coli that ar... |
The current understanding of insect cell metabolism is very limited. In order to gain some insight into the growth and metabolism of insect cells Spodoptera frugiperda (Sf9), a comprehensive characterization of culture conditions for cells grown in the IPL-41 medium was made by measuring the amino acid composition of t... |
A flow cytometric method was developed for the assay of beta-galactosidase in single Escherichia coli cells. A new fluorogenic substrate for beta-galactosidase, C(12)FDG, contains a lipophilic group that allows the substrate to penetrate through cell membranes under normal conditions. When the substrate is hydrolyzed b... |
The dilution rate of an ultrafiltration membrane bioreactor in the enzymatic hydrolysis of cellulose was optimized using the kinetic model developed by Fan and Lee.(4) The sequence of optimal dilution rates was found to generally consist of an initial period of a minimal value (batch period), a subsequent period of max... |
The toxicity of homologous series of organic solvents has been investigated for the gram-positive bacteria, Arthrobacter sp. and Nocardia sp., and the gram-negative bacteria, Acinetobacter sp. and Pseudomonas sp. The hydrophobicity of the solvent, expressed by its logP(octanol), proves to be a good measure for the toxi... |
Triglyceride hydrolysis using Chromobacterium viscosum lipase B in a reversed micellar media was investigated in a batch-type reactor. The dynamic evolution of the product concentration was analyzed using several mechanistic models, both from the literature and developed in this work. A kinetic model with nonlinear pro... |
Olive oil hydrolysis using Chromobacterium viscosum lipase B in a reversed micellar media was investigated in a membrane reactor. The dynamic evolution of the product concentration both in the concentrate and permeate stream was analyzed using a mechanistic model previously developed by us and further modified in this ... |
Pressure affects enzyme function in nonaqueous media. Activation volumes have been determined and provide evidence that the primary effect of pressure is to enhance the stripping of water off an enzyme in polar organic solvents and leads to decreased enzymatic activity. Activation volumes of subtilisin Carlsberg in org... |
Stationary phase cell suspension cultures of Agrobacterium tumefaciens transformed Lithospermum erythrorhizon respond to additions of sucrose-rich (C-rich) medium with a 2-3-fold increase in the accumulation of shikonin derivatives and a 3-3.5-fold increase in the accumulation of soluble phenolics while showing a modes... |
The effect of water activity (a(w)) of the reaction medium on the enzymatic synthesis of cephalexin (CEX) from 7-amino-3-deacetoxycephalosporanic acid (7-ADCA) and D-alpha-phenylglycine methyl ester (PGM) was investigated using the alpha-amino acid ester hydrolase enzyme from Xanthomonas citri. It was found that the sy... |
Numerical and Monte Carlo simulations of horseradish peroxidase-catalyzed phenolic polymerizations have been performed. Kinetic constants for the simulations were fit to data from the oxidation and polymerization of bisphenol A. Simulations of peroxidase-catalyzed phenolic polymerization were run as a function of enzym... |
Microporous polymer supports for the immobilization of lipase have been prepared by the polymerization of a concentrated emulsion precursor. The concentrated emulsion consists of a mixture of styrene and divinyl-benzene containing a suitable surfactant and an initiator as the continuous phase and water as the dispersed... |
An enzymatic method for removal of phenols from industrial wastewater was investigated. Phenols in an aqueous solution were removed after treatment with mushroom tyrosinase. The reduction order of substituted phenols is catechol > p-cresol > p-chlorophenol > phenol > p-methoxyphenol. In the treatment of tyrosinase alon... |
Fermentation of xylose by Clostridium thermosaccharolyticum was studied in batch and continuous culture in which the limiting nutrient was either xylose, phosphate, or ammonia. Transient results obtained in continuous cultures with batch grown inoculum and progressively higher feed substrate concentrations exhibited et... |
A kinetic study of the activity of mushroom polyphenol oxidase in an organic system was carried out to obtain detailed enzyme kinetic data in relation to optimization of reaction conditions and substrate specificity. A simple method for consistent measurement of reaction rates in the heterogeneous enzyme/organic solven... |
The activities of six purified Thermomonospora fusca cellulases and Trichoderma reesei CBHI and CBHII were determined on filter paper, swollen cellulose, and CMC. A simple method to measure the soluble and insoluble reducing sugar products from the hydrolysis of filter paper was found to effectively distinguish between... |
A new group-specific affinity membrane using metal chelates as ligands and inorganic glass hollow fiber microfiltration membranes as support matrices is developed and tested. The study focused on developing the optimum activation and coupling procedures to bind the chelating agent (iminodiacetic acid, IDA) to the surfa... |
A means of rapidly renaturing denatured protein was devised and evaluated. Three liquids were laminarly layered in a centrifuge tube, in which two solutions sandwiched liquid paraffin so as to form a pseudolipid bilayer. Denatured and aggregted protein placed on the upper surface of liquid paraffin was renatured as it ... |
Asn182 --> Ala Aspergillus awamori glucoamylase expressed in Saccharomyces cerevisiae had a first-order thermodeactivation coefficient 40% that of wild-type glucoamylase at pH 4.5 between 60 degrees and 65 degrees C, caused by the elimination of an Asn-Gly sequence subject to deamidation and eventual chain breakage. Ab... |
Recent studies have shown that circadian clock genes are expressed in various peripheral tissues, raising the possibility that multiple clocks regulate circadian physiology. To study clock gene expression in the rhesus macaque pituitary gland we used gene microarray data and found that the pituitary glands of young and... |
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive and irreversible loss of memory and other cognitive functions. Substantial evidence based on genetic, neuropathological and biochemical data has established the central role of beta-amyloid protein (betaAP) in this pathology. Although... |
Current knowledge of the pathogenesis of basal ganglia disorders, such as Huntington's disease (HD) and Parkinson's disease (PD) appoints a central role to a dysfunction in mitochondrial metabolism. The development of animal models, based upon the use of mitochondrial toxins has been successfully introduced to reproduc... |
Prostaglandins, in particular PGE(2) and prostacyclin PGI(2) have diverse biological effects. Most importantly, they are involved in inflammation and pain. Prostaglandins in nano- and micromolar concentrations sensitize nerve cells, i.e. make them more sensitive to electrical or chemical stimuli. Sensitization arises f... |
Bv8 is a small protein secreted by frog skin. Mammalian homologues of Bv8, the prokineticins PK1 and PK2, and their G-protein coupled receptors PKR1 and PKR2 have been identified and linked to several biological effects. Bv8 elicits a dose-dependent reduction in nociceptive threshold to thermal and mechanical stimuli a... |
Persistent pain, a common clinical condition, could be caused by inflammation, tissue injury secondary to trauma or surgery, and nerve injuries. It is often inadequately controlled by current treatments, such as opioids and nonsteroidal anti-inflammatory drugs. The PDZ (Postsynaptic density 95, Discs large, and Zonula ... |
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